Modern hair dyeing has developed from its initiation in the 1950's to the point where, today, it is the third largest product type in the hair category following shampoos and conditioners.
A wide variety of hair dyes or colorants have been developed, many of which involve oxidation of selected organic compounds or combinations of compounds with oxidizing agents such as hydrogen peroxide. Other known oxidizing agents for use with such compounds include perborates, persulfates, and perhalates, particularly periodates. These oxidizing agents are generally employed as ammonium salts or as salts of alkali metals. In the course of the development it has been learned that the applicability of an oxidant to one or more oxidizable substrates does not permit the prediction that the same oxidant or an apparently similar oxidant will be useful of oxidizing another oxidizable substrate to achieve a desirable color change in human hair.
Despite the large number of hair dyeing compositions and processes which have been developed, the art is constantly searching for methods and compositions to improve the efficiency of the hair coloring process, decrease the time required, impart desirable tints and tones to the hair and avoid the use of hydrogen peroxide, which may be damaging to the hair or to the skin which it contacts.